Mold of typographical slug-casting machines



Sept. 29, 1936. c. A. ALBRECHT MOLD OF TYPOGRAPHICAL SLUG CASTING MACHINES Filed March 29, 1935 Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE MOLD OF TYPOGRAPHICAL SLUG-CASTING MACHINES York Application March 29, 1935, Serial No. 13,625 In Germany April 24, 1934 8 Claims. (Cl. 199-55) In typographical slug-casting machines it has already been proposed to provide the molds with core members for the purpose of forming recesses in slugs of the larger sizes, such as headletter or display slugs, to reduce the weight of the slugs and the quantity of metal used. Such core members are used in molds for casting L- shaped or U-shaped slugs, and form, in known manner, transverse ribs or stays connecting the arm or arms of the slug body with the character bearing face. As heretofore formed. such ribs are usually slightly tapered inwardly from the type face, or, especially in the case of L-shaped 1 slugs, slightly tapered upwardly from the transverse arm. The inclination of the rib surfaces to the face of the slug, however, in the known constructions, is very slight, and the consequence of this is that when the slug in course of solidification is contracted, its ribs are drawn against the mold core members and there is a liability of jamming when the slug is ejected.

The object of the present invention is to overcome this difficulty. For this purpose the core members are so shaped that the ribs formed on the slugs are sharply tapered along the lateral surfaces directed towards the transverse centre of the slug, the angle of inclination of the said surfaces to the transverse centre line being not less than the angle of friction of the slug metal relatively to the core metal. The rib or ribs nearest the centre of the slug may retain their usual form. During solidification the slug is therefore held in the centre and contracts from the sides towards the centre; the inclined surfaces on the ribs of the slug thus press against the corresponding surfaces on the core members and the slugs are drawn away or loosened from the core members in consequence of the angle of inclination, the ejecting operation being thereby made considerably easier. The sides of the ribs directed outwardly, i. e. towards the ends of the slug, may be given any preferred form.

The accompanying drawing illustrates by way of example one constructional form of the invention as applied to the production of a U- shaped slug. In the said drawing:-

Figure 1 is a vertical section of a mold with a slug therein, and the metal pot throat and mouthpiece;

Figure 2 is a plan of the mold with the cap removed, showing the slug in longitudinal section;

Figure 3 is a longitudinal section of the slug, and

Figure 4 is a transverse section of the slug shown in Figure 3.

Referring to Figure 1 of the drawing, a is the metal pot throat having a mouthpiece I) through which molten metal is forced into the mold. The mold consists of a cap 0 and a body d which are spaced apart at the ends by means of intermediate members or end liners, these parts constituting respectively the side and end walls of the casting cavity. For the purpose of casting recessed slugs core members e are provided in the mold. The said core members e in the constructional form illustrated, are formed on a ledge 1 extending longitudinally of the mold slot. The mold illustrated is thus adapted to cast a substantially U-shaped slug, the two arms g and h of which are connected by ribs 1' (see Figure 4) As so far described the arrangement is substantially as heretofore proposed.

According to the invention, in order to prevent the ribs i of a cast slug adhering tightly to the core members e through the contraction of the slug which takes place during solidification, the surfaces m and n of the core members e, that is to say, the surfaces thereof which are directed away from the transverse centre line 7c of the mold, are inclined outwardly from the front surface of the core members at an angle to the said centre line not less than the angle of friction of the solidified slug metal relatively to the metal from which the core members are made. The result of this is, that during the solidification of the slug, the pressure of its surfaces m ,n (Figure 3) against the adjacent surfaces m, n of the core members will cause the slug to be drawn away automatically from the core members and become loosened in the mold by what amounts to a very slight ejecting movement, and in this way the ejection of the slug is made considerably easier. The other surfaces of the core members, i. e., the surfaces directed towards the transverse centre line of the mold, may be parallel to the said centre line, although they may be inclined inwardly from the front surface of the core members, at an angle preferably corresponding to that heretofore proposed.

It is important that the inclination according to the invention should be applied to the outer core members, i. e., those located away from the centre, because the slug contracts from the outside towards the centre. In the constructional example illustrated, the inclination has been applied to both surfaces of the central core member, but it would suffice for the construction of such central core member to be carried out in the usual form with straight or slightly inclined surfaces, seeing that in view of the small distance between the two innermost ribs of the slug, the amount of contraction can be only extremely small.

The invention is not only applicable to U- shaped slugs, in which the ribs are located between two parallel arms, but also to L-shaped slugs, in which the ribs are free on one side, and finally also for Very thick slugs which comprise both a U-shaped and an L-shaped section, and are fitted with ribs, both between the armsiof the U-shaped section and also in the free space of the L-shap'ed section.

Having described my invention, I declare that What I claim and desire to secure by Letters Patent is:

1. A mold for a typographical.slugecasting machine having core members for the formation of recessed slugs, characterized by at leastonecore member on each side of the transverse centre line of the mold,"having its outer surface inclined outwardly from the said centre line at an angle thereto not'less than "the angle of friction ofcthe solidified slug metal relativelyzto *thecore metal.

2. A mold for a typographical slug-casting machine having =coremembers for the formation of recessed slugs, characterized by at "least one core member on each side of the transverse centre line of the mold, having :its outer surface inclined outwardly from the said centreline at an angle thereto greater than the angle 'of friction of the solidified slug metal relatively to the 'core' metal.

3."A mold'for a typographical slug-casting machinehaving core members for the formation of recessed slugs, characterized by .at least one core member on'each side of the'transverse centre line of the'rnold being unsymmetricaily tapered .to- Wards the front of the mold, its-rearwardly 'extending outer surface being inclined at an angle to its front-surface greater "than that at which the 'rearwardly extending inner surface is so inclined, and said angle of inclination 'of the'rearwardlyextending outer surface=beingxnot less than the angle of friction of "theisolidifi'ed slug f metal relatively to the core metal.

4. A mold for atypographicalslug-castingmachine having'core members for the formation of recessed slugs, characterized by at least one=core core metal.

:5. .Amold for a typographical slug-casting machine having core members for the formation of recessed slugs, said core members comprising a symmetrically tapered central member and a plurality ofunsymmetrically tapered members located on each sideof said central member, the

outer surfaces of said unsymmetrically tapered members being inclined outwardly from the transverse centre line of the mold at an angle thereto notlesslthan the angle of friction of the solidified slug metal relatively to the core metal.

.6. A recessed typographical slug having on each side-of its transverse centre line at least one of the recess 'walls facing said centre line inclined at an angle thereto not less than the angle of frictionof the slug metal relatively to the metal ofthe mold core used for the formation of the recesses.

7.1A typographical slug having a plurality of tapered ribs extending inwardly from'the rear of the typeface and-disposed on each side of the transverse centre line of the slug, and comprising at least one rib on each side of the surface ofwhich directed towards said centre'line is inclined thereto at an angle not less than the angle of friction of the slug metal relatively to the-metal of the mold core used for the formation of the ribs.

' -8. A mold'for a'typographical'slug casting machine havingcore members for the formation of recessed slugs, said core members having their outer surfaces inclined outwardly from the transverse center line of the mold at an angle thereto not less than'the angle of friction of the solidified slugmetal relatively to the core metal, whereby to cause the slug, in shrinking upon cooling, to eject-itself partially from the mold.

CHRISTIAN AUGUSTUS ALBRECHT. 

